The label "Move or resize existing windows" is not accurate because we do no longer allow moving or resizing main window regardless of the option state.
It should be changed to something like "Move or resize popup windows".

Comment on attachment 566919[details][diff][review]
patch v2 [ui-r=faaborg]
moveResizePopupWindows? moveResizeWindows2 is kind of silly.
The checkbox id could be updated as well, although this is less important since it's unused.